Editing Coevolution

{{Short description|Two or more species influencing each other's evolution}}
{{Good article}}
[[File:Dasyscolia ciliata.jpg|thumb|upright=1.5|The pollinating wasp ''[[Dasyscolia ciliata]]'' in [[pseudocopulation]] with a flower of ''[[Ophrys speculum]]''<ref name=Pijl/>]]
In biology, '''coevolution''' occurs when two or more [[species]] reciprocally affect each other's [[evolution]] through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well as [[gene-culture coevolution]].

[[Charles Darwin]] mentioned evolutionary interactions between [[flowering plant]]s and [[insect]]s in ''[[On the Origin of Species]]'' (1859). Although he did not use the word coevolution, he suggested how plants and insects could evolve through reciprocal evolutionary changes. Naturalists in the late 1800s studied other examples of how interactions among species could result in reciprocal evolutionary change. Beginning in the 1940s, plant pathologists developed breeding programs that were examples of human-induced coevolution. Development of new crop plant varieties that were resistant to some diseases favored rapid evolution in pathogen populations to overcome those plant defenses. That, in turn, required the development of yet new resistant crop plant varieties, producing an ongoing cycle of reciprocal evolution in crop plants and diseases that continues to this day.

Coevolution as a major topic for study in nature expanded rapidly from the 1960s, when Daniel H. Janzen showed coevolution between [[acacia]]s and ants (see below) and [[Paul R. Ehrlich]] and [[Peter H. Raven]] suggested how [[Escape and radiate coevolution|coevolution between plants and butterflies]] may have contributed to the diversification of species in both groups. The theoretical underpinnings of coevolution are now well-developed (e.g., the geographic mosaic theory of coevolution), and demonstrate that coevolution can play an important role in driving major evolutionary transitions such as the evolution of sexual reproduction or shifts in [[ploidy]].<ref name="itct">{{cite book |last=Nuismer |first=Scott |date=2017|title=Introduction to Coevolutionary Theory |url=https://www.macmillanlearning.com/Catalog/product/introductiontocoevolutionarytheory-firstedition-nuismer/valueoptions |location=New York |publisher=W.F. Freeman |page=395 |isbn=978-1-319-10619-5 |access-date=2019-05-02 |archive-url=https://web.archive.org/web/20190502204606/https://www.macmillanlearning.com/Catalog/product/introductiontocoevolutionarytheory-firstedition-nuismer/valueoptions |archive-date=2019-05-02 |url-status=dead}}</ref><ref name="Thompson, John N">{{Cite book |title=Relentless evolution |last=Thompson |first=John N. |isbn=978-0-226-01861-4 |location=Chicago |oclc=808684836 |date=2013-04-15}}</ref> More recently, it has also been demonstrated that coevolution can influence the structure and function of ecological communities, the evolution of groups of mutualists such as plants and their pollinators, and the dynamics of infectious disease.<ref name="itct" /><ref>{{Cite journal |last1=Guimarães |first1=Paulo R. |last2=Pires |first2=Mathias M. |last3=Jordano |first3=Pedro |last4=Bascompte|first4=Jordi |last5=Thompson |first5=John N. |date=October 2017 |title=Indirect effects drive coevolution in mutualistic networks |journal=Nature |volume=550 |issue=7677 |pages=511–514 |doi=10.1038/nature24273 |pmid=29045396 |bibcode=2017Natur.550..511G |s2cid=205261069}}</ref>

Each party in a coevolutionary relationship exerts [[evolutionary pressure|selective pressures]] on the other, thereby affecting each other's evolution. Coevolution includes many forms of [[mutualism (biology)|mutualism]], [[host–parasite coevolution|host-parasite]], and [[predation|predator-prey]] relationships between species, as well as [[intraspecific competition|competition within]] or [[interspecific competition|between species]]. In many cases, the selective pressures drive an [[evolutionary arms race]] between the species involved. '''Pairwise''' or '''specific coevolution''', between exactly two species, is not the only possibility; in '''multi-species coevolution''', which is sometimes called '''guild''' or '''diffuse coevolution''', several to many species may evolve a trait or a group of traits in reciprocity with a set of traits in another species, as has happened between the flowering plants and [[pollinator|pollinating]] insects such as [[bee]]s, [[fly|flies]], and [[beetle]]s. There are a suite of specific hypotheses on the mechanisms by which groups of species coevolve with each other.<ref name="Thompson, John N. 2005">{{Cite book|last=Thompson |first=John N. |title=The geographic mosaic of coevolution |date=2005|publisher=University of Chicago Press |isbn=978-0-226-11869-7 |location=Chicago |oclc=646854337}}</ref>

Coevolution is primarily a biological concept, but researchers have applied it by analogy to fields such as [[computer science]], [[sociology]], and [[astronomy]].

== Mutualism ==

{{main|Mutualism (biology)}}

Coevolution is the [[evolution]] of two or more [[species]] which reciprocally affect each other, sometimes creating a [[Mutualism (biology)|mutualistic relationship]] between the species. Such relationships can be of many different types.<ref>{{cite book |title=Coevolution |editor1-link=Douglas J. Futuyma|editor1-last=Futuyma|editor1-first = D. J.|editor2-first= M.|editor2-last= Slatkin |year=1983 |publisher=[[Sinauer Associates]] |isbn=978-0-87893-228-3 }}</ref><ref name="t24" />

=== Flowering plants ===

Flowers appeared and diversified relatively suddenly in the fossil record, creating what [[Charles Darwin]] described as the "abominable mystery" of how they had evolved so quickly; he considered whether coevolution could be the explanation.<ref name="CardinalDanforth2013"/><ref>{{cite journal |last=Friedman |first=W. E. |date=January 2009 |title=The meaning of Darwin's 'abominable mystery' |journal=American Journal of Botany |volume=96 |issue=1 |pages=5–21 |doi=10.3732/ajb.0800150 |pmid=21628174 }}</ref> He first mentioned coevolution as a possibility in ''[[On the Origin of Species]]'', and developed the concept further in ''[[Fertilisation of Orchids]]'' (1862).<ref name=t24>{{cite book |first=John N. |last=Thompson |title=The coevolutionary process |publisher=[[University of Chicago Press]] |location=Chicago |year=1994 |isbn=978-0-226-79760-1 |url=https://books.google.com/books?id=AyXPQzEwqPIC&q=Wallace+%22creation+by+law%22+Angr%C3%A6cum&pg=PA27 |access-date=2009-07-27}}</ref><ref name=origins94>{{cite book |last=Darwin |first=Charles |year=1859 |title=On the Origin of Species |edition=1st |location=London |publisher=John Murray |url=http://darwin-online.org.uk/content/frameset?itemID=F373&viewtype=text&pageseq=1 |access-date=2009-02-07}}</ref><ref name=orchids1>{{cite book |last=Darwin |first=Charles |year=1877 |title=On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing |location=London |publisher=John Murray |edition=2nd |url=http://darwin-online.org.uk/content/frameset?itemID=F801&viewtype=text&pageseq=1 |access-date=2009-07-27}}</ref>

====Insects and insect-pollinated flowers====
{{Further|Entomophily}}
[[File:Apis mellifera - Melilotus albus - Keila.jpg|thumb|upright|[[Honey bee]] taking a reward of [[nectar]] and collecting pollen in its [[pollen basket]]s from [[Melilotus albus|white melilot]] flowers]]

Modern [[entomophily|insect-pollinated (entomophilous) flowers]] are conspicuously coadapted with insects to ensure pollination and in return to reward the [[pollinator]]s with nectar and pollen. The two groups have coevolved for over 100 million years, creating a complex network of interactions. Either they evolved together, or at some later stages they came together, likely with pre-adaptations, and became mutually adapted.<ref name=Lunau>{{cite journal |last=Lunau |first=Klaus |title=Adaptive radiation and coevolution — pollination biology case studies |journal=Organisms Diversity & Evolution |date=2004 |volume=4 |issue=3 |pages=207–224 |doi=10.1016/j.ode.2004.02.002 |doi-access= |bibcode=2004ODivE...4..207L }}</ref><ref>{{cite book |last=Pollan |first=Michael |author-link=Michael Pollan |title=The Botany of Desire: A Plant's-eye View of the World |publisher=Bloomsbury |isbn=978-0-7475-6300-6 |title-link=The Botany of Desire |year=2003}}</ref>

Several highly successful [[insect]] groups—especially the [[Hymenoptera]] (wasps, bees and ants) and [[Lepidoptera]] (butterflies and moths) as well as many types of [[Diptera]] (flies) and [[Coleoptera]] (beetles)—evolved in conjunction with [[flowering plant]]s during the [[Cretaceous]] (145 to 66 million years ago). The earliest bees, important pollinators today, appeared in the early Cretaceous.<ref name=Bristol>{{cite web |title=Coevolution of angiosperms and insects |url=http://palaeo.gly.bris.ac.uk/Palaeofiles/Angiosperms/coevolution.htm |publisher=University of Bristol Palaeobiology Research Group |access-date=16 January 2017 |archive-url=https://web.archive.org/web/20161220033247/http://palaeo.gly.bris.ac.uk/Palaeofiles/Angiosperms/coevolution.htm |archive-date=20 December 2016 |url-status=dead }}</ref> A group of wasps [[sister clade|sister]] to the bees evolved at the same time as flowering plants, as did the Lepidoptera.<ref name=Bristol/> Further, all the major [[clade]]s of bees first appeared between the middle and late Cretaceous, simultaneously with the adaptive radiation of the [[eudicots]] (three quarters of all angiosperms), and at the time when the angiosperms became the world's dominant plants on land.<ref name="CardinalDanforth2013">{{cite journal |last1=Cardinal |first1=Sophie |last2=Danforth |first2=Bryan N. |title=Bees diversified in the age of eudicots |journal=Proceedings of the Royal Society B |date=2013 |doi=10.1098/rspb.2012.2686 |volume=280 |issue=1755 |pages=20122686 |pmid=23363629 |pmc=3574388}}</ref>

At least three aspects of flowers appear to have coevolved between flowering plants and insects, because they involve communication between these organisms. Firstly, flowers communicate with their pollinators by scent; insects use this scent to determine how far away a flower is, to approach it, and to identify where to land and finally to feed. Secondly, flowers attract insects with patterns of stripes leading to the rewards of nectar and pollen, and colours such as blue and ultraviolet, to which their eyes are sensitive; in contrast, bird-pollinated flowers tend to be red or orange. Thirdly, flowers such as [[Ophrys|some orchids]] mimic females of particular insects, deceiving males into [[pseudocopulation]].<ref name=Bristol/><ref name=Pijl>{{cite book |first1=Leendert |last1=van der Pijl |first2=Calaway H. |last2=Dodson |title=Orchid Flowers: Their Pollination and Evolution |chapter-url=https://archive.org/details/orchidflowersthe0000pijl |chapter-url-access=registration |chapter=Chapter 11: Mimicry and Deception |publisher=[[University of Miami]] Press |location=Coral Gables |year=1966 |pages=[https://archive.org/details/orchidflowersthe0000pijl/page/129 129–141] |isbn=978-0-87024-069-0}}</ref>

The [[yucca]], ''Yucca whipplei'', is pollinated exclusively by ''Tegeticula maculata'', a [[Tegeticula|yucca moth]] that depends on the yucca for survival.<ref>{{cite web|title=Pollination Partnerships Fact Sheet |work=Flora of North America |year=2004 |first=Claire |last= Hemingway |page= 2|url=http://fna.huh.harvard.edu/files/imported/Outreach/FNAfs_yucca.pdf |quote=Yucca and Yucca Moth|archive-url = https://web.archive.org/web/20110817052152/http://fna.huh.harvard.edu/files/imported/Outreach/FNAfs_yucca.pdf |archive-date = 17 August 2011}}</ref> The moth eats the seeds of the plant, while gathering pollen. The pollen has evolved to become very sticky, and remains on the mouth parts when the moth moves to the next flower. The yucca provides a place for the moth to lay its eggs, deep within the flower away from potential predators.<ref>{{cite journal |last1=Pellmyr |first1=Olle |last2=Leebens-Mack |first2=James |title=Forty million years of mutualism: Evidence for Eocene origin of the yucca-yucca moth association |journal=PNAS |date=August 1999 |pmid=10430916 |volume=96 |issue=16 |pmc=17753 |pages=9178–9183 |bibcode=1999PNAS...96.9178P |doi=10.1073/pnas.96.16.9178 |doi-access=free }}</ref>

====Birds and bird-pollinated flowers====
{{Further|Ornithophily}}
[[File:Purple-throated carib hummingbird feeding.jpg|thumb|left|[[Purple-throated carib]] feeding from and pollinating a flower]]

[[Hummingbird]]s and [[Ornithophily|ornithophilous]] (bird-pollinated) flowers have evolved a [[mutualism (biology)|mutualistic]] relationship. The flowers have [[nectar]] suited to the birds' diet, their color suits the birds' vision and their shape fits that of the birds' bills. The blooming times of the flowers have also been found to coincide with hummingbirds' breeding seasons. The floral characteristics of ornithophilous plants vary greatly among each other compared to closely related insect-pollinated species. These flowers also tend to be more ornate, complex, and showy than their insect pollinated counterparts. It is generally agreed that plants formed coevolutionary relationships with insects first, and ornithophilous species diverged at a later time. There is not much scientific support for instances of the reverse of this divergence: from ornithophily to insect pollination. The diversity in floral phenotype in ornithophilous species, and the relative consistency observed in bee-pollinated species can be attributed to the direction of the shift in pollinator preference.<ref>{{cite journal |last1=Kay |first1=Kathleen M.|last2=Reeves |first2=Patrick A. |last3=Olmstead |first3=Richard G. |last4=Schemske|first4=Douglas W. |s2cid=2991957|title=Rapid speciation and the evolution of hummingbird pollination in neotropical Costus subgenus Costus (Costaceae): evidence from nrDNA ITS and ETS sequences |journal=American Journal of Botany |date=2005 |volume=92 |issue=11|pages=1899–1910 |doi=10.3732/ajb.92.11.1899 |pmid=21646107|doi-access= }}</ref>

Flowers have converged to take advantage of similar birds.<ref name="Brown">{{cite journal |last1=Brown |first1=James H. |last2=Kodric-Brown |first2=Astrid |title=Convergence, Competition, and Mimicry in a Temperate Community of Hummingbird-Pollinated Flowers |s2cid=53604204 |journal=Ecology |year=1979 |volume=60 |issue=5 |pages=1022–1035 |doi=10.2307/1936870|jstor=1936870|bibcode=1979Ecol...60.1022B }}</ref> Flowers compete for pollinators, and adaptations reduce unfavourable effects of this competition. The fact that birds can fly during inclement weather makes them more efficient pollinators where bees and other insects would be inactive. Ornithophily may have arisen for this reason in isolated environments with poor insect colonization or areas with plants which flower in the winter.<ref name="Brown"/><ref>{{cite journal |last1=Cronk |first1=Quentin |last2=Ojeda |first2=Isidro |title=Bird-pollinated flowers in an evolutionary and molecular context |journal=Journal of Experimental Botany |date=2008 |volume=59 |issue=4 |pages=715–727 |doi=10.1093/jxb/ern009|pmid=18326865|doi-access=free }}</ref> Bird-pollinated flowers usually have higher volumes of nectar and higher sugar production than those pollinated by insects.<ref name="Stiles">{{cite journal |last=Stiles |first=F. Gary |title=Geographical Aspects of Bird Flower Coevolution, with Particular Reference to Central America |journal=Annals of the Missouri Botanical Garden |year=1981 |volume=68 |issue=2 |pages=323–351 |doi=10.2307/2398801 |jstor=2398801 |bibcode=1981AnMBG..68..323S |s2cid=87692272 |url=https://www.biodiversitylibrary.org/part/38387 }}</ref> This meets the birds' high energy requirements, the most important determinants of flower choice.<ref name="Stiles"/> In ''[[Mimulus]]'', an increase in red pigment in petals and flower nectar volume noticeably reduces the proportion of pollination by bees as opposed to hummingbirds; while greater flower surface area increases bee pollination. Therefore, red pigments in the flowers of ''Mimulus cardinalis'' may function primarily to discourage bee visitation.<ref>{{cite journal |last1=Schemske |first1=Douglas W. |last2=Bradshaw |first2=H.D. |title=Pollinator preference and the evolution of floral traits in monkeyflowers (''Mimulus'') |journal=Proceedings of the National Academy of Sciences |date=1999 |volume=96 |issue=21 |pages=11910–11915 |doi=10.1073/pnas.96.21.11910|pmid=10518550 |bibcode=1999PNAS...9611910S |pmc=18386|doi-access=free }}</ref> In ''[[Penstemon]]'', flower traits that discourage bee pollination may be more influential on the flowers' evolutionary change than 'pro-bird' adaptations, but adaptation 'towards' birds and 'away' from bees can happen simultaneously.<ref>{{cite journal |last1=Castellanos|first1=M. C. |last2=Wilson |first2=P. |last3=Thomson |first3=J.D. |title='Anti-bee' and 'pro-bird' changes during the evolution of hummingbird pollination in Penstemon flowers |journal=Journal of Evolutionary Biology |date=2005 |volume=17 |issue=4 |pages=876–885 |doi=10.1111/j.1420-9101.2004.00729.x |pmid=15271088|doi-access=free }}</ref> However, some flowers such as ''[[Heliconia angusta]]'' appear not to be as specifically ornithophilous as had been supposed: the species is occasionally (151 visits in 120 hours of observation) visited by ''[[Trigona]]'' stingless bees. These bees are largely pollen robbers in this case, but may also serve as pollinators.<ref>{{cite journal |last1=Stein |first1=Katharina |last2=Hensen |first2=Isabell |title=Potential Pollinators and Robbers: A Study of the Floral Visitors of Heliconia Angusta (Heliconiaceae) And Their Behaviour |journal=Journal of Pollination Ecology |date=2011 |volume=4 |issue=6 |pages=39–47|doi=10.26786/1920-7603(2011)7|doi-access=free }}</ref>

Following their respective breeding seasons, several species of hummingbirds occur at the same locations in [[North America]], and several hummingbird flowers bloom simultaneously in these habitats. These flowers have [[convergent evolution|converged]] to a common [[morphology (biology)|morphology]] and color because these are effective at attracting the birds. Different lengths and curvatures of the [[petal#Corolla|corolla]] tubes can affect the efficiency of extraction in hummingbird species in relation to differences in bill morphology. Tubular flowers force a bird to orient its bill in a particular way when probing the flower, especially when the bill and corolla are both curved. This allows the plant to place [[pollen]] on a certain part of the bird's body, permitting a variety of morphological [[co-adaptation]]s.<ref name="Stiles"/>

Ornithophilous flowers need to be conspicuous to birds.<ref name="Stiles"/> Birds have their greatest spectral sensitivity and finest hue discrimination at the red end of the [[visual spectrum]],<ref name="Stiles"/> so red is particularly conspicuous to them. Hummingbirds may also be able to see ultraviolet "colors". The prevalence of ultraviolet patterns and nectar guides in nectar-poor entomophilous (insect-pollinated) flowers warns the bird to avoid these flowers.<ref name="Stiles"/> Each of the two subfamilies of hummingbirds, the [[Phaethornithinae]] (hermits) and the [[Trochilinae]], has evolved in conjunction with a particular set of flowers. Most Phaethornithinae species are associated with large [[monocotyledon]]ous herbs, while the Trochilinae prefer [[dicotyledon]]ous plant species.<ref name="Stiles"/>
<!-- could extend examples of mutualism indefinitely - might mention fish/anemone [[cleaning symbiosis]] etc.
[[File:Common clownfish curves dnsmpl.jpg|thumb|[[Ocellaris clownfish]] and [[Heteractis magnifica|Ritter's sea anemones]] live together in a [[mutualism (biology)|mutual]] service-service symbiosis, the fish driving off butterfly fish and the anemone's tentacles protecting the fish from predators.]]
-->

===Fig reproduction and fig wasps===
[[File:Ficus plant.jpg|thumb|left|A [[Common fig|fig]] exposing its many tiny matured, seed-bearing [[gynoecia]]. These are pollinated by the fig wasp, ''[[Blastophaga psenes]]''. In the cultivated fig, there are also asexual varieties.<ref name=Suleman/>]]
{{Main|Reproductive coevolution in Ficus}}
The genus ''[[Ficus]]'' is composed of 800 species of vines, shrubs, and trees, including the cultivated fig, defined by their [[syconia]], the fruit-like vessels that either hold female flowers or pollen on the inside. Each fig species has its own [[fig wasp]] which (in most cases) pollinates the fig, so a tight mutual dependence has evolved and persisted throughout the genus.<ref name=Suleman>{{cite journal |last1=Suleman |first1=Nazia |last2=Sait |first2=Steve |last3=Compton |first3=Stephen G. |title=Female figs as traps: Their impact on the dynamics of an experimental fig tree-pollinator-parasitoid community |journal=Acta Oecologica |volume=62 |year=2015 |pages=1–9 |doi=10.1016/j.actao.2014.11.001 |bibcode=2015AcO....62....1S|url=http://eprints.whiterose.ac.uk/85568/7/Female%20plants%20as%20traps%20paper%20%283%29.pdf }}</ref>

[[File:Ant - Pseudomyrmex species, on Bull Thorn Acacia (Acacia cornigera) with Beltian bodies, Caves Branch Jungle Lodge, Belmopan, Belize - 8505045055.jpg|thumb|right|''Pseudomyrmex'' ant on bull thorn acacia (''[[Vachellia cornigera]]'') with Beltian bodies that provide the ants with protein<ref name="Hölldobler-532"/>]]

===Acacia ants and acacias===

{{Main|Pseudomyrmex ferruginea}}

The [[acacia ant]] (''Pseudomyrmex ferruginea'') is an obligate plant ant that protects at least five species of "Acacia" (''[[Vachellia]]''){{efn|The acacia ant protects at least 5 species of "Acacia", now all renamed to ''Vachellia'': ''[[Vachellia chiapensis|V. chiapensis]]'', ''[[Vachellia collinsii|V. collinsii]]'', ''[[Vachellia cornigera|V. cornigera]]'', ''[[Vachellia hindsii|V. hindsii]]'', and ''[[Vachellia sphaerocephala|V. sphaerocephala]]''.}} from preying insects and from other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and its larvae.<ref name="Hölldobler-532">{{cite book |last1=Hölldobler |first1=Bert |last2=Wilson |first2=Edward O. |title=The ants |publisher=Harvard University Press |year=1990 |url=https://archive.org/details/ants0000hlld |url-access=registration |isbn=978-0-674-04075-5 |pages=[https://archive.org/details/ants0000hlld/page/532 532]–533}}</ref><ref>{{cite web |website=National Geographic |title=Acacia Ant Video |url=http://video.nationalgeographic.com/video/player/animals/bugs-animals/ants-and-termites/ant_acaciatree.html|url-status=dead|archive-url=https://web.archive.org/web/20071107085438/http://video.nationalgeographic.com/video/player/animals/bugs-animals/ants-and-termites/ant_acaciatree.html|archive-date=2007-11-07}}</ref> Such mutualism is not automatic: other ant species exploit trees without reciprocating, following different [[evolutionary strategy|evolutionary strategies]]. These cheater ants impose important host costs via damage to tree reproductive organs, though their net effect on host fitness is not necessarily negative and, thus, becomes difficult to forecast.<ref>{{cite journal |last1=Palmer |first1=Todd M. |last2=Doak |first2=Daniel F. |last3=Stanton |first3=Maureen L. |last4=Bronstein |first4=Judith L. |last5=Kiers |first5=E. Toby |last6=Young |first6=Truman P. |last7=Goheen |first7=Jacob R. |last8=Pringle |first8=Robert M. |display-authors=3 |title=Synergy of multiple partners, including freeloaders, increases host fitness in a multispecies mutualism |journal=Proceedings of the National Academy of Sciences |volume=107 |issue=40 |date=2010-09-20 |issn=0027-8424 |doi=10.1073/pnas.1006872107 |pages=17234–17239 |pmid=20855614 |pmc=2951420 |bibcode=2010PNAS..10717234P |doi-access=free }}</ref><ref>{{cite journal |title=Kinship and incompatibility between colonies of the acacia ant ''Pseudomyrex ferruginea'' |journal=Behavioral Ecology and Sociobiology |first1=Alex |last1=Mintzer |last2=Vinson |first2=S. B. |volume=17 |issue=1 |pages=75–78 |doi=10.1007/bf00299432 |jstor=4599807 |year=1985 |bibcode=1985BEcoS..17...75M |s2cid=9538185 }}</ref>

==Hosts and parasites==
{{Main|Host–parasite coevolution}}

===Parasites and sexually reproducing hosts===
[[Host–parasite coevolution]] is the coevolution of a [[host (biology)|host]] and a [[parasite]].<ref name="Woolhouse">{{cite journal |doi=10.1038/ng1202-569 |last1=Woolhouse |first1=M. E. J. |last2=Webster |first2=J. P. |last3=Domingo |first3=E. |last4=Charlesworth |first4=B. |last5=Levin |first5=B. R. |title=Biological and biomedical implications of the coevolution of pathogens and their hosts |journal=[[Nature Genetics]] |date=December 2002 |pmid=12457190 |volume=32 |issue=4 |pages=569–77 |url=http://www.era.lib.ed.ac.uk/bitstream/1842/689/2/Charlesworth_Woolhouse.pdf |hdl=1842/689 |s2cid=33145462 |hdl-access=free }}</ref> A general characteristic of many viruses, as [[obligate parasite]]s, is that they coevolved alongside their respective hosts. Correlated mutations between the two species enter them into an evolution arms race. Whichever organism, host or parasite, that cannot keep up with the other will be eliminated from their habitat, as the species with the higher average population fitness survives. This race is known as the [[Red Queen hypothesis]].<ref>{{cite journal |last=Van Valen |first=L. |date=1973 |title=A New Evolutionary Law |journal=Evolutionary Theory |volume=1 |pages=1–30}} cited in: [http://pespmc1.vub.ac.be/REDQUEEN.html The Red Queen Principle]</ref> The Red Queen hypothesis predicts that sexual reproduction allows a host to stay just ahead of its parasite, similar to the [[Red Queen's race]] in ''[[Through the Looking-Glass]]'': "it takes all the running ''you'' can do, to keep in the same place".<ref>{{cite book |last=Carroll |first=Lewis |author-link=Lewis Carroll |orig-year=1871 |title=Through the Looking-glass: And what Alice Found There |url=https://books.google.com/books?id=cJJZAAAAYAAJ |publisher=Macmillan |date=1875 |page=42 |quote=it takes all the running ''you'' can do, to keep in the same place.}}</ref> The host reproduces sexually, producing some offspring with immunity over its parasite, which then evolves in response.<ref>{{cite journal |doi=10.1038/srep10004 |last=Rabajante |first=J. |display-authors=etal |title=Red Queen dynamics in multi-host and multi-parasite interaction system |journal=[[Scientific Reports]] |year=2015 |volume=5 |pages=10004 |pmid=25899168 |pmc=4405699 |bibcode=2015NatSR...510004R}}</ref>

The parasite–host relationship probably drove the prevalence of sexual reproduction over the more efficient asexual reproduction. It seems that when a parasite infects a host, sexual reproduction affords a better chance of developing resistance (through variation in the next generation), giving sexual reproduction variability for fitness not seen in the asexual reproduction, which produces another generation of the organism susceptible to infection by the same parasite.<ref>{{cite web |title=Sexual reproduction works thanks to ever-evolving host, parasite relationships |website=PhysOrg |url=https://phys.org/news/2011-07-sexual-reproduction-ever-evolving-host-parasite.html |date=7 July 2011}}</ref><ref>{{cite journal |last1=Morran |first1=L.T. |author2=Schmidt, O.G. |author3=Gelarden, I.A. |author4=Parrish, R.C. II |author5= Lively, C.M. |title=Running with the Red Queen: Host-Parasite Coevolution Selects for Biparental Sex |journal=Science |volume=333 |issue=6039 |pages=216–8 |date=8 July 2011 |id=Science.1206360 |bibcode=2011Sci...333..216M |doi=10.1126/science.1206360 |pmid=21737739 |pmc=3402160}}</ref><ref>{{cite encyclopedia |author=Hogan, C. Michael |date=2010 |url=https://editors.eol.org/eoearth/wiki/Virus |title=Virus |encyclopedia=Encyclopedia of Earth |editor=Cutler Cleveland |editor2=Sidney Draggan}}</ref> Coevolution between host and parasite may accordingly be responsible for much of the genetic diversity seen in normal populations, including blood-plasma polymorphism, protein polymorphism, and histocompatibility systems.<ref>{{cite journal |author1=Anderson, R. |author2=May, R. |date=October 1982 |title=Coevolution of hosts and parasites |journal=Parasitology |volume=85 |issue=2 |pages=411–426 |doi=10.1017/S0031182000055360 |pmid=6755367|s2cid=26794986 }}</ref>

[[File:Reed warbler cuckoo.jpg|upright|thumb|[[Brood parasite]]: [[Eurasian reed warbler]] raising a [[common cuckoo]]<ref name=Weiblen/>]]

===Brood parasites===
{{Main|Brood parasitism}}

[[Brood parasite|Brood parasitism]] demonstrates close coevolution of host and parasite, for example in some [[cuckoo]]s. These birds do not make their own nests, but lay their eggs in nests of other species, ejecting or killing the eggs and young of the host and thus having a strong negative impact on the host's reproductive fitness. Their eggs are camouflaged as eggs of their hosts, implying that hosts can distinguish their own eggs from those of intruders and are in an evolutionary arms race with the cuckoo between camouflage and recognition. Cuckoos are counter-adapted to host defences with features such as thickened eggshells, shorter incubation (so their young hatch first), and flat backs adapted to lift eggs out of the nest.<ref name=Weiblen>{{cite web |last1=Weiblen |first1=George D. |title=Interspecific Coevolution |url=http://geo.cbs.umn.edu/Weiblen2003.pdf |publisher=Macmillan |date=May 2003}}</ref><ref>{{cite journal |last1=Rothstein |first1=S.I |year=1990 |title=A model system for coevolution: avian brood parasitism |journal=Annual Review of Ecology and Systematics |volume=21 |pages=481–508 |doi=10.1146/annurev.ecolsys.21.1.481}}</ref><ref>{{Cite book |last=Davies |first=Nicholas B. |others=McCallum, James (Wildlife artist) |title=Cuckoo : cheating by nature |date=7 April 2015 |isbn=978-1-62040-952-7 |edition=First U.S. |location=New York, NY |oclc=881092849}}</ref>

===Antagonistic coevolution===

Antagonistic coevolution is seen in the [[harvester ant]] species ''[[Pogonomyrmex barbatus]]'' and ''[[Pogonomyrmex rugosus]]'', in a relationship both parasitic and mutualistic. The queens are unable to produce worker ants by mating with their own species. Only by crossbreeding can they produce workers. The winged females act as parasites for the males of the other species as their sperm will only produce sterile hybrids. But because the colonies are fully dependent on these hybrids to survive, it is also mutualistic. While there is no genetic exchange between the species, they are unable to evolve in a direction where they become too genetically different as this would make crossbreeding impossible.<ref name="Herrmann Cahan pp. 20141771–20141771">{{cite journal |last1=Herrmann |first1=M. |last2=Cahan |first2=S. H. |title=Inter-genomic sexual conflict drives antagonistic coevolution in harvester ants |journal=Proceedings of the Royal Society B: Biological Sciences |volume=281 |issue=1797 |date=29 October 2014 |doi=10.1098/rspb.2014.1771 |pmid=25355474 |pages=20141771 |pmc=4240986}}</ref>

==Predators and prey==
[[File:Leopard kill - KNP - 001.jpg|thumb|left|Predator and prey: a [[leopard]] killing a [[Cape bushbuck|bushbuck]]]]
{{Main|Predation}}

[[Predator]]s and prey interact and coevolve: the predator to catch the prey more effectively, the prey to escape. The coevolution of the two mutually imposes [[selective pressure]]s. These often lead to an [[evolutionary arms race]] between prey and predator, resulting in [[anti-predator adaptation]]s.<ref>{{cite web|title=Predator-Prey Relationships|url=https://necsi.edu/predator-prey-relationships|publisher=New England Complex Systems Institute|access-date=17 January 2017}}</ref>

The same applies to [[herbivore]]s, animals that eat plants, and the plants that they eat.  [[Paul R. Ehrlich]] and [[Peter H. Raven]] in 1964 proposed the theory of [[escape and radiate coevolution]] to describe the evolutionary diversification of plants and butterflies.<ref>{{cite journal |last1=Ehrlich |first1=Paul R. |author1-link=Paul R. Ehrlich |last2=Raven |first2=Peter H. |author2-link= Peter H. Raven |year=1964 |title=Butterflies and Plants: A Study in Coevolution |journal=Evolution |volume=18 |issue=4 |pages=586–608 |doi=10.2307/2406212 |jstor=2406212}}</ref> In the [[Rocky Mountains]], [[red squirrel]]s and [[crossbill]]s (seed-eating birds) compete for seeds of the [[lodgepole pine]]. The squirrels get at pine seeds by gnawing through the cone scales, whereas the crossbills get at the seeds by extracting them with their unusual crossed mandibles. In areas where there are squirrels, the lodgepole's cones are heavier, and have fewer seeds and thinner scales, making it more difficult for squirrels to get at the seeds. Conversely, where there are crossbills but no squirrels, the cones are lighter in construction, but have thicker scales, making it more difficult for crossbills to get at the seeds. The lodgepole's cones are in an evolutionary arms race with the two kinds of herbivore.<ref name="Berkeley">{{cite web |title=Coevolution |url=https://evolution.berkeley.edu/evolibrary/article/evo_33 |publisher=University of California Berkeley |access-date=17 January 2017}} and the two following pages of the web article.</ref>

[[File:Drosophila.melanogaster.couple.2.jpg|thumb|upright|[[Sexual conflict]] has been studied in ''[[Drosophila melanogaster]]'' (shown mating, male on right).]]

==Competition==
{{Main|Intraspecific competition|Interspecific competition}}

Both [[intraspecific competition]], with features such as [[sexual conflict]]<ref>{{cite journal |doi=10.1098/rstb.2005.1785 |title=Sexual conflict over mating and fertilization: An overview |year=2006 |last1=Parker |first1=G. A. |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=361 |issue=1466 |pages=235–59 |pmid=16612884 |pmc=1569603}}</ref> and [[sexual selection]],<ref name="UCL">{{cite web|title=Biol 2007 - Coevolution|url=https://www.ucl.ac.uk/~ucbhdjm/courses/b242/Coevol/Coevol.html|publisher=[[University College, London]]|access-date=19 January 2017}}</ref> and [[interspecific competition]], such as between predators, may be able to drive coevolution.<ref>{{cite journal |last1=Connell |first1=Joseph H. |s2cid=5576868 |title=Diversity and the Coevolution of Competitors, or the Ghost of Competition Past |journal=Oikos |date=October 1980 |volume=35 |issue=2 |pages=131–138 |doi=10.2307/3544421 |jstor=3544421|bibcode=1980Oikos..35..131C }}</ref>

Intraspecific competition can result in [[sexual antagonistic coevolution]], an evolutionary relationship analogous to an [[evolutionary arms race|arms race]], where the evolutionary fitness of the sexes is counteracted to achieve maximum reproductive success. For example, some [[insect]]s reproduce using [[traumatic insemination]], which is disadvantageous to the female's health. During mating, males try to maximise their fitness by inseminating as many females as possible, but the more times a female's [[abdomen]] is punctured, the less likely she is to survive, reducing her fitness.<ref name="Siva-Jothy et al.">{{cite journal  |last1=Siva-Jothy |first1=M. T. |last2=Stutt |first2=A. D. |doi=10.1098/rspb.2002.2260 |title=A matter of taste: Direct detection of female mating status in the bedbug |journal=Proceedings of the Royal Society B: Biological Sciences |year=2003 |volume=270 |issue=1515 |pages=649–652 |pmid=12769466 |pmc=1691276 }}</ref>

== Multispecies ==

[[File:Amegilla on long tube of Acanthus ilicifolius flower.jpg|thumb|upright|Long-tongued bees and long-tubed flowers coevolved, whether pairwise or "diffusely" in groups known as guilds.<ref name=Juenger/>]]

The types of coevolution listed so far have been described as if they operated pairwise (also called specific coevolution), in which traits of one species have evolved in direct response to traits of a second species, and vice versa. This is not always the case. Another evolutionary mode arises where evolution is reciprocal, but is among a group of species rather than exactly two. This is variously called guild or diffuse coevolution. For instance, a trait in several species of [[flowering plant]], such as offering its [[nectar]] at the end of a long tube, can coevolve with a trait in one or several species of pollinating insects, such as a long proboscis. More generally, flowering plants are pollinated by insects from different families including [[bee]]s, [[fly|flies]], and [[beetle]]s, all of which form a broad [[guild (ecology)|guild]] of [[pollinator]]s which respond to the nectar or pollen produced by flowers.<ref name=Juenger>Juenger, Thomas, and [[Joy Bergelson]]. "Pairwise versus diffuse natural selection and the multiple herbivores of scarlet gilia, Ipomopsis aggregata." Evolution (1998): 1583–1592.</ref><ref>{{cite book |last1=Gullan |first1=P. J. |last2=Cranston |first2=P. S. |date=2010 |title=The Insects: An Outline of Entomology |url=https://archive.org/details/insectsoutlineen00pjgu |url-access=limited |publisher=Wiley |edition=4th |isbn=978-1-118-84615-5 |pages=[https://archive.org/details/insectsoutlineen00pjgu/page/n315 291]–293}}</ref><ref>{{cite journal |last1=Rader |first1=Romina |last2=Bartomeus |first2=Ignasi |display-authors=etal |title=Non-bee insects are important contributors to global crop pollination |journal=PNAS |date=2016 |volume=113 |issue=1 |doi=10.1073/pnas.1517092112 |pmid=26621730 |pmc=4711867 |pages=146–151 |bibcode=2016PNAS..113..146R|doi-access=free }}</ref>

== Geographic mosaic theory ==

{{main|Mosaic coevolution}}

'''Mosaic coevolution''' is a theory in which [[geographic location]] and [[community ecology]] shape differing coevolution between strongly interacting species in multiple populations. These populations may be separated by space and/or time. Depending on the ecological conditions, the interspecific interactions may be mutualistic or antagonistic.<ref name="Thompson 2005">{{cite journal |last1=Thompson |first1=John N. |title=Coevolution: The Geographic Mosaic of Coevolutionary Arms Races |journal=Current Biology |date=24 December 2005 |volume=15 |issue=24 |pages=R992–R994 |doi=10.1016/j.cub.2005.11.046 |pmid=16360677 |s2cid=16874487 |doi-access=free |bibcode=2005CBio...15.R992T }}</ref> In mutualisms, both partners benefit from the interaction, whereas one partner generally experiences decreased fitness in antagonistic interactions. Arms races consist of two species adapting ways to "one up" the other. Several factors affect these relationships, including hot spots, cold spots, and trait mixing.<ref name="Gomulkiewicz 2000">{{cite journal |last1=Gomulkiewicz |first1=Richard |last2=Thompson |first2=John N. |last3=Holt |first3=Robert D. |last4=Nuismer |first4=Scott L. |last5=Hochberg |first5=Michael E. |title=Hot Spots, Cold Spots, and the Geographic Mosaic Theory of Coevolution. |journal=The American Naturalist |date=1 August 2000 |volume=156 |issue=2 |pages=156–174 |doi=10.1086/303382 |pmid=10856199 |bibcode=2000ANat..156..156G |s2cid=4442185 }}</ref> Reciprocal selection occurs when a change in one partner puts pressure on the other partner to change in response. Hot spots are areas of strong reciprocal selection, while cold spots are areas with no reciprocal selection or where only one partner is present.<ref name="Gomulkiewicz 2000"/> The three constituents of geographic structure that contribute to this particular type of coevolution are: natural selection in the form of a geographic mosaic, hot spots often surrounded by cold spots, and trait remixing by means of [[genetic drift]] and [[gene flow]].<ref name="Gomulkiewicz 2000"/> Mosaic, along with general coevolution, most commonly occurs at the population level and is driven by both the [[biotic material|biotic]] and the abiotic environment. These environmental factors can constrain coevolution and affect how far it can escalate.<ref name="Anderson 2008">{{cite journal |last1=Anderson |first1=Bruce |last2=Johnson |first2=Steven D. |title=The Geographical Mosaic of Coevolution in a Plant–Pollinator Mutualism |journal=Evolution |date=2008 |volume=62 |issue=1 |pages=220–225 |doi=10.1111/j.1558-5646.2007.00275.x |pmid=18067570 |s2cid=8643749 |doi-access=free }}</ref>

== Outside biology ==

Coevolution is primarily a biological concept, but has been applied to other fields by [[analogy]].

=== In algorithms ===

{{See also|Evolutionary computation}}

Coevolutionary algorithms are used for generating [[artificial life]] as well as for optimization, [[Games and learning|game learning]] and [[machine learning]].<ref>Potter M.; De Jong, K. (1995) Evolving Complex Structures via Cooperative Coevolution, Fourth Annual Conference on Evolutionary Programming, San Diego, California.</ref><ref>Potter M. (1997) The Design and Computational Model of Cooperative Coevolution, PhD thesis, George Mason University, Fairfax, Virginia.</ref><ref>{{cite journal |last1=Potter |first1=Mitchell A. |last2=De Jong |first2=Kenneth A. |title=Cooperative Coevolution: An Architecture for Evolving Coadapted Subcomponents |journal=Evolutionary Computation |date=2000 |volume=8 |issue=1 |pages=1–29 |doi=10.1162/106365600568086 |pmid=10753229 |citeseerx=10.1.1.134.2926 |s2cid=10265380}}</ref><ref>Weigand, P.; Liles, W.; De Jong, K. (2001) An empirical analysis of collaboration methods in cooperative coevolutionary algorithms. Proceedings of the Genetic and Evolutionary Computation Conference.</ref><ref>Weigand, P. (2003) An Analysis of Cooperative Coevolutionary Algorithms, PhD thesis, George Mason University, Fairfax, Virginia, 2003.</ref> [[Daniel Hillis]] added "co-evolving parasites" to prevent an optimization procedure from becoming stuck at [[Maximum and minimum|local maxima]].<ref>{{cite journal |last=Hillis |first=W. D. |year=1990 |title=Co-evolving parasites improve simulated evolution as an optimization procedure |journal=Physica D: Nonlinear Phenomena |volume=42 |issue=1–3 |pages=228–234 |doi=10.1016/0167-2789(90)90076-2|bibcode=1990PhyD...42..228H}}</ref> [[Karl Sims]] coevolved virtual creatures.<ref>{{cite web |last=Sims |first=Karl |title=Evolved Virtual Creatures |url=http://www.karlsims.com/evolved-virtual-creatures.html|publisher=Karl Sims |access-date=17 January 2017 |date=1994}}</ref>

===In architecture===

The concept of coevolution was introduced in architecture by the Danish architect-urbanist [[Henrik Valeur]] as an antithesis to "star-architecture".<ref>{{cite web |url=http://henrikvaleur.dk/biography/ |title=Henrik Valeur's biography |access-date=2015-08-29}}</ref> As the curator of the Danish Pavilion at the 2006 Venice Biennale of Architecture, he created an exhibition-project on coevolution in urban development in China; it won the Golden Lion for Best National Pavilion.<ref>{{cite web |url=http://www.dac.dk/en/dac-life/exhibitions/2006/co-evolution/about-co-evolution/ |title=About Co-evolution |publisher=Danish Architecture Centre |access-date=2015-08-29 |url-status=dead |archive-url=https://web.archive.org/web/20151120011414/http://www.dac.dk/en/dac-life/exhibitions/2006/co-evolution/about-co-evolution/ |archive-date=2015-11-20 }}</ref><ref>{{cite web |url=https://movingcities.org/interviews/henrik-valeur_domuschina/ |title= An interview with Henrik Valeur |publisher=Movingcities |access-date=2015-10-17 |date=2007-12-17}}</ref><ref>{{cite book |last=Valeur |first=Henrik |title=Co-evolution: Danish/Chinese Collaboration on Sustainable Urban Development in China|publisher=Danish Architecture Centre|year= 2006|location= Copenhagen |isbn=978-87-90668-61-7 |page=12}}</ref><ref>{{cite book |last=Valeur |first=Henrik |title=India: the Urban Transition - a Case Study of Development Urbanism |publisher=Architectural Publisher B |year=2014 |isbn=978-87-92700-09-4 |title-link=India: the Urban Transition |page=22}}</ref>

At the School of Architecture, Planning and Landscape, [[Newcastle University]], a coevolutionary approach to architecture has been defined as a design practice that engages students, volunteers and members of the local community in practical, experimental work aimed at "establishing dynamic processes of learning between users and designers."<ref>{{cite journal |last=Farmer |first=Graham |year=2017 |title=From Differentiation to Concretisation: Integrative Experiments in Sustainable Architecture |journal=Societies |volume=3 |issue=35 |page=18 |doi=10.3390/soc7040035 |doi-access=free }}</ref>

===In cosmology and astronomy===
In his book ''The Self-organizing Universe'', [[Erich Jantsch]] attributed the entire evolution of the [[cosmos]] to coevolution.

In [[astronomy]], an emerging theory proposes that [[black hole]]s and [[galaxy|galaxies]] develop in an interdependent way analogous to biological coevolution.<ref>{{cite journal |last=Gnedin |first=Oleg Y. |display-authors=etal|title=Co-Evolution of Galactic Nuclei and Globular Cluster Systems |journal=The Astrophysical Journal |volume=785 |issue=1 |doi=10.1088/0004-637X/785/1/71 |bibcode=2014ApJ...785...71G |pages=71|arxiv=1308.0021|year=2014 |s2cid=118660328 }}</ref>

===In management and organization studies===
Since year 2000, a growing number of management and organization studies discuss coevolution and coevolutionary processes. Burgelman <ref>{{Cite journal |last=Burgelman |first=Robert A. |date=2002-06-01 |title=Strategy as Vector and the Inertia of Coevolutionary Lock-in |url=https://journals.sagepub.com/doi/10.2307/3094808 |journal=Administrative Science Quarterly |language=EN |volume=47 |issue=2 |pages=325–357 |doi=10.2307/3094808 |issn=0001-8392|url-access=subscription }}</ref> examines the ecosystem of partners of the Intel corporation, and illustrates how Intel shapes and is shaped by its networks of partners.  Abatecola el al. (2020) reveals a prevailing scarcity in explaining what processes substantially characterize coevolution in these fields, meaning that specific analyses about where this perspective on socio-economic change is, and where it could move toward in the future, are still missing.<ref>{{cite journal |doi=10.1016/j.techfore.2020.119964 |title=Do organizations really co-evolve? Problematizing co-evolutionary change in management and organization studies |year=2020 |journal=Technological Forecasting and Social Change |volume= 155 |last1=Abatecola |first1=Gianpaolo |last2=Breslin |first2=Dermot |last3=Kask |first3=Johan |page=119964 |issn=0040-1625|doi-access=free }}</ref> Park, Dahlander, and Piezunka <ref>{{Cite journal |last=Park |first=Sanghyun |last2=Piezunka |first2=Henning |last3=Dahlander |first3=Linus |date=February 2024 |title=Coevolutionary Lock-In in External Search |url=https://journals.aom.org/doi/abs/10.5465/amj.2022.0710?journalCode=amj |journal=Academy of Management Journal |volume=67 |issue=1 |pages=262–288 |doi=10.5465/amj.2022.0710 |issn=0001-4273|url-access=subscription }}</ref> illustrate the mechanisms underlying co-evolutionally lockin in social systems: studying crowdsourcing initiatives they illustrate how externals respond to selection of the focal organization; externals whose contributions arte appreciated continue, others select out of contributing, or adjust the kind of contributions. The focal organization thus ends up with more homogenous input. 

===In sociology===
In ''Development Betrayed: The End of Progress and A Coevolutionary Revisioning of the Future'' (1994)<ref>{{cite book |last=Norgaard |first=Richard B. |title=Development Betrayed: The End of Progress and a Coevolutionary Revisioning of the Future |year=1994 |publisher=Routledge}}</ref> [[Richard Norgaard]] proposes a coevolutionary cosmology to explain how social and environmental systems influence and reshape each other.<ref>{{cite journal |last1=Glasser |first1=Harold |year=1996 |title=Development Betrayed: The End of Progress and A Coevolutionary Revisioning of the Future by Richard B. Norgaard |journal=Environmental Values |volume=5 |issue=3 |pages=267–270|doi=10.1177/096327199600500308 |jstor=30301478 |s2cid=259156528 }}</ref> In ''Coevolutionary Economics: The Economy, Society and the Environment'' (1994) John Gowdy suggests that: "The economy, society, and the environment are linked together in a coevolutionary relationship".<ref>{{cite book |last=Gowdy |first=John |title=Coevolutionary Economics: The Economy, Society and the Environment |year=1994 |publisher=Springer |pages=1–2}}</ref>

===In technology===
{{Further|Software ecosystem}}

[[Computer software]] and [[computer hardware|hardware]] can be considered as two separate components but tied intrinsically by coevolution. Similarly, [[operating system]]s and computer [[application software|applications]], [[web browser]]s, and [[web application]]s. All these systems depend upon each other and advance through a kind of evolutionary process. Changes in hardware, an operating system or web browser may introduce new features that are then incorporated into the corresponding applications running alongside.<ref name="D’Hondt Volder Mens Wuyts 2002">{{cite book |last1=D’Hondt |first1=Theo |last2=Volder |first2=Kris |last3=Mens |first3=Kim |last4=Wuyts |first4=Roel |title=Software Architectures and Component Technology |chapter=Co-Evolution of Object-Oriented Software Design and Implementation |publisher=Springer US |publication-place=Boston, MA |year=2002 |isbn=978-1-4613-5286-0 |doi=10.1007/978-1-4615-0883-0_7 |pages=207–224}}</ref> The idea is closely related to the concept of "joint optimization" in [[sociotechnical system]]s analysis and design, where a system is understood to consist of both a "technical system" encompassing the tools and hardware used for production and maintenance, and a "social system" of relationships and procedures through which the technology is tied into the goals of the system and all the other human and organizational relationships within and outside the system. Such systems work best when the technical and social systems are deliberately developed together.<ref>{{cite journal |last1=Cherns |first1=A. |year=1976 |title=The principles of sociotechnical design |journal=Human Relations |volume=29 |issue=8 |page=8 |doi=10.1177/001872677602900806 |doi-access= }}</ref>

==See also==
*[[Evolutionary arms race]]
*[[Bak–Sneppen model]]
*[[CoEvolution Quarterly]]
*[[Coextinction]]
*[[Ecological fitting]]
*[[Escape and radiate coevolution]]
*[[Genomics of domestication]]

==Notes==
{{Notelist}}

==References==
{{Reflist}}

==External links==
*[http://www.cosmolearning.com/video-lectures/coevolution-6703/ Coevolution], video of lecture by [[Stephen C. Stearns]] ([[Open Yale Courses]])

{{Evolution}}
{{Evolutionary psychology}}

[[Category:Ecological processes]]
[[Category:Environmental terminology]]
[[Category:Evolution of the biosphere]]
[[Category:Evolutionary biology]]
[[Category:Habitat]]